1. Field of the Invention
The present invention relates generally to a system and method for inspecting replacement components in a processing line, and more particularly to a checking system for sensing the presence of and identifying whether the proper replacement component has been installed at a work station to ensure better process reliability.
2. Prior Art
In processing lines, such as those for semiconductor fabrication, various components are used at work stations in the line that contain exhaustible supplies of processing materials, such as photo-resist in the case of the semiconductor fabrication line. When, frequently during the process, it is time to replace a container in which the material has become exhausted with a container having a new supply, it is important that the replacement container be properly placed at the station and that it actually hold the appropriate material intended for the process. As the replacement operation is subject to human error, incidents have occurred where due to a faulty installation or of the installing of a container with the wrong material, large amounts of process product has been contaminated and lost.
3. Problem to be Solved
It is therefore a problem in the art to ensure that a replacement component in a processing line is the proper one and properly installed for the process being carried out.
It is accordingly an object of the present invention to provide a a system and method for reliably inspecting replacement components in a processing line.
It is another object of the invention to provide an automatic checking system for sensing the presence of and identifying whether the proper replacement component has been installed at a work station in a processing line to ensure better process reliability.
It is also a particular object of the invention to provide a method and means for confirming that a replacement container with a new supply of photo-resist is the intended one for use in a semiconductor fabrication line in which it is installed.
The present invention involves an inspecting system for detecting the presence of and identifying whether the proper replacement component has been installed at a work station in a processing line, and particularly an exemplary automatic container checking system which is capable of reading identifying information on the container indicative of a characteristic thereof and comparing the information read with stored information indicative of a desired characteristic to determine whether there is a match. In the absence of a match, an alarm or other means can be used, by way of notification of a problem or to automatically stop the processing line.
In a preferred embodiment, the container is provided with a suitable detectable marker, such as a label marked with chracteristic identifying information, e.g., a bar-code, or a color, or with a magnetic card, indicating the type or contents of the container, and, if desired, positioning information to indicate a proper location and/or orientation. The container is mounted in position on a machine or other support for supplying material, such as photo-resist, for use in a semiconductor fabrication process. A sensing device, e.g., a bar-code reader or magnetic card, is provided for reading the label information and communicating it to a control device such as a computer, which has an associated memory including a suitable database that is pre-loaded with selected identification information in keeping with the contents and position appropriate for the station at which the sensing device is disposed. The machine or processing line is normally inactive when a replacement container, filled with photo-resist, is placed in position at the station. If the contents and/or the position information detected on the label matches the selected related information stored in the database, when the machine and line are actuated, the processing will continue. If there is a mismatch, an alarm may be set off, or the machine or line automatically stopped by a signal from the computer, to permit a close inspection of the container and removal, if appropriate, to avoid contamination and loss of the processed product, e.g., scrapping of a considerable number of valuable semiconductor wafers. Accordingly, the invention by sensing the presence of and identifying whether the proper replacement component has been installed at a work station in a processing line and by stopping the processing when appropriate, ensures better process reliability and increased product yield rate.